<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>web worker test</title>
</head>
<body>
    <input type="number" value="1" id="num1">+
    <input type="number" value="2" id="num2">
    <button id="btn">=</button>
    <strong id="result">0</strong>
    <script src="./index.js"></script>
</body>
</html>